Infection with the Moloney retrovirus and genome integration in the host cell genome results in development of lymphomas in mice. Provirus Integration of Moloney Kinase (PIM-Kinase) was identified as one of the frequent proto-oncogenes capable of being transcriptionally activated by this retrovirus integration event (Cuypers H T et al., “Murine leukemia virus-induced T-cell lymphomagenesis: integration of proviruses in a distinct chromosomal region,” Cell 37(1):141-50 (1984); Selten G, et al., “Proviral activation of the putative oncogene Pim-1 in MuLV induced T-cell lymphomas” EMBO J 4(7):1793-8 (1985)), thus establishing a correlation between over-expression of this kinase and its oncogenic potential. Sequence homology analysis demonstrated that there are three highly homologous Pim-Kinases (Pim1, 2 & 3), Pim1 being the proto-oncogene originally identified by retrovirus integration. Furthermore, transgenic mice over-expressing Pim1 or Pim2 show increased incidence of T-cell lymphomas (Breuer M et al., “Very high frequency of lymphoma induction by a chemical carcinogen in pim-1 transgenic mice” Nature 340(6228):61-3 (1989)), while over-expression in conjunction with c-myc is associated with incidence of B-cell lymphomas (Verbeek S et al., “Mice bearing the E mu-myc and E mu-pim-1 transgenes develop pre-B-cell leukemia prenatally” Mol Cell Biol 11(2):1176-9 (1991)). Thus, these animal models establish a strong correlation between Pim over-expression and oncogenesis in hematopoietic malignancies.
In addition to these animal models, Pim over-expression has been reported in many human malignancies. Pim1, 2 & 3 over-expression is frequently observed in hematopoietic malignancies (Amson R et al., “The human protooncogene product p33pim is expressed during fetal hematopoiesis and in diverse leukemias,” PNAS USA 86(22):8857-61 (1989); Cohen A M et al., “Increased expression of the hPim-2 gene in human chronic lymphocytic leukemia and non-Hodgkin lymphoma,” Leuk Lymph 45(5):951-5 (2004), Huttmann A et al., “Gene expression signatures separate B-cell chronic lymphocytic leukaemia prognostic subgroups defined by ZAP-70 and CD38 expression status,” Leukemia 20:1774-1782 (2006)) and in prostate cancer (Dhanasekaran S M, et al., “Delineation of prognostic biomarkers in prostate cancer,” Nature 412(6849):822-6 (2001); Cibull T L, et al., “Overexpression of Pim-1 during progression of prostatic adenocarcinoma,” J Clin Pathol 59(3):285-8 (2006)), while over-expression of Pim3 is frequently observed in hepatocellular carcinoma (Fujii C, et al., “Aberrant expression of serine/threonine kinase Pim-3 in hepatocellular carcinoma development and its role in the proliferation of human hepatoma cell lines,” Int J Cancer 114:209-218 (2005)) and pancreatic cancer (Li Y Y et al., “Pim-3, a proto-oncogene with serine/threonine kinase activity, is aberrantly expressed in human pancreatic cancer and phosphorylates bad to block bad-mediated apoptosis in human pancreatic cancer cell lines,” Cancer Res 66(13):6741-7 (2006)).
Pim1, 2 & 3 are Serine/Threonine kinases that normally function in survival and proliferation of hematopoietic cells in response to growth factors and cytokines. Cytokines signaling through the Jak/Stat pathway leads to activation of transcription of the Pim genes and synthesis of the proteins. No further post-translational modifications are required for the Kinase Pim activity. Thus, signaling downstream is primarily controlled at the transcriptional/translational and protein turnover level. Substrates for Pim kinases include regulators of apoptosis such as the Bcl-2 family member BAD (Aho T et al., “Pim-1 kinase promotes inactivation of the pro-apoptotic Bad protein by phosphorylating it on the Ser112 gatekeeper site: FEBS Letters 571: 43-49 (2004)), cell cycle regulators such as p21WFA1/CIP1 (Wang Z, et al., “Phosphorylation of the cell cycle inhibitor p21Cip1/WAF1 by Pim-1 kinase,” Biochem Biophys Acta 1593:45-55 (2002)), CDC25A (1999), C-TAK (Bachmann M et al., “The Oncogenic Serine/Threonine Kinase Pim-1 Phosphorylates and Inhibits the Activity of Cdc25C-associated Kinase 1 (C-TAK1). A novel role for Pim-1 at the G2/M cell cycle checkpoint,” J Biol Chem 179:48319-48328 (2004)) and NuMA (Bhattacharya N, et al., “Pim-1 associates with protein complexes necessary for mitosis,” Chromosoma 111(2):80-95 (2002)) and the protein synthesis regulator 4EBP1 (Hammerman P S et al., “Pim and Akt oncogenes are independent regulators of hematopoietic cell growth and survival,” Blood 105(11):4477-83 (2005)). The effects of Pim(s) in these regulators are consistent with a role in protection from apoptosis and promotion of cell proliferation and growth. Thus, over-expression of Pim(s) in cancer is thought to play a role in promoting survival and proliferation of cancer cells and, therefore, their inhibitions should be an effective way of treating cancers in which they are over-expressed. In fact several reports indicate that knocking down expression of Pim(s) with siRNA results in inhibition of proliferation and cell death (Dai J M, et al., “Antisense oligodeoxynucleotides targeting the serine/threonine kinase Pim-2 inhibited proliferation of DU-145 cells,” Acta Pharmacol Sin 26(3):364-8 (2005); Fujii et al. 2005; Li et al. 2006).
Furthermore, mutational activation of several well known oncogenes in hematopoietic malignancies is thought to exert its effects at least in part through Pim(s). For example, targeted down-regulation of Pim expression impairs survival of hematopoietic cells transformed by Flt3 and BCR/ABL (Adam et al. 2006). Thus, inhibitors to Pim1, 2 and 3 would be useful in the treatment of these malignancies.
In addition to a potential role in cancer treatment and myeloproliferative diseases, such inhibitor could be useful to control expansion of immune cells in other pathologic condition such as autoimmune diseases, allergic reactions and in organ transplantation rejection syndromes. This notion is supported by the findings that differentiation of Th1 Helper T-cells by IL-12 and IFN-α results in induction of expression of both Pim1 and Pim2 (Aho T et al., “Expression of human Pim family genes is selectively up-regulated by cytokines promoting T helper type 1, but not T helper type 2, cell differentiation,” Immunology 116: 82-88 (2005)). Moreover, Pim(s) expression is inhibited in both cell types by the immunosuppressive TGF-β (Aho et al. 2005). These results suggest that Pim kinases are involved in the early differentiation process of Helper T-cells, which coordinate the immunological responses in autoimmune diseases, allergic reaction and tissue transplant rejection. Recent reports demonstrate that Pim kinase inhibitors show activity in animal models of inflammation and autoimmune diseases. See J E Robinson “Targeting the Pim Kinase Pathway for Treatment of Autoimmune and Inflammatory Diseases,” for the Second Annual Conference on Anti-Inflammatories: Small Molecule Approaches,” San Diego, Calif. (Conf. April 2011; Abstract published earlier on-line).
A continuing need exists for compounds that inhibit the proliferation of capillaries, inhibit the growth of tumors, treat cancer, modulate cell cycle arrest, and/or inhibit molecules such as Pim1, Pim2 and Pim3, and pharmaceutical formulations and medicaments that contain such compounds. A need also exists for methods of administering such compounds, pharmaceutical formulations, and medicaments to patients or subjects in need thereof. The present invention addresses such needs.
Earlier patent applications have described compounds that inhibit Pims and function as anticancer therapeutics, see, e.g., WO2012/004217, WO2010/026124, WO 2008/106692 and WO2011/124580, and as treatment for inflammatory conditions such as Crohn's disease, inflammatory bowel disease, rheumatoid arthritis, and chronic inflammatory diseases, see e.g., WO 2008/022164. The present invention provides compounds that inhibit activity of one or more Pims, preferably two or more Pims, more preferably Pim1, Pim2 and Pim3, at nanomolar levels (e.g., IC-50 under 100 nM or under 50 nM) and exhibit distinctive characteristics that may provide improved therapeutic effects and pharmacokinetic properties, such as reduced drug-drug interactions associated with inhibition of cytochrome oxidases, relative to compounds previously disclosed. Compounds of the invention contain novel substitution combinations on one or more rings that provide these distinctive properties and are suitable for treating Pim-related conditions such as those described herein.